Semiconductor oxidation apparatus and method of producing semiconductor element

Abstract

A semiconductor oxidation apparatus is provided with a sealable oxidation chamber defined by walls, a base provided within the oxidation chamber and configured to support a semiconductor sample, a supply part configured to supply water vapor into the oxidation chamber to oxidize a specific portion of the semiconductor sample, a monitoring window provided in one of the walls of the oxidation chamber and disposed at a position capable of confronting the semiconductor sample supported on the base, a monitoring part provided outside the oxidation chamber and capable of confronting the semiconductor sample supported on the base via the monitoring window, and an adjusting part configured to adjust a distance between the base and the monitoring part.

1. A method for producing a semiconductor element, comprising:
 placing within a water vapor atmosphere a semiconductor sample that includes a mesa having a semiconductor layer including Al and As; 
 forming a current constricting part and a current injecting part that is surrounded by the current constricting part in the semiconductor layer by oxidizing the semiconductor layer from a peripheral end of the semiconductor layer appearing at an outer peripheral side surface of the mesa towards an inner radial direction so as to leave a central portion of the semiconductor layer non-oxidized; 
 interrupting an oxidation process at least once during oxidation of the semiconductor layer; and 
 monitoring an oxidation rate of the semiconductor layer while the oxidation process is interrupted; and 
 exhausting an atmosphere gas within the oxidation chamber by vacuum while the oxidation process is interrupted, 
 wherein said monitoring includes:
 moving the semiconductor sample within an oxidation chamber to a position where the mesa is adjacent to a monitoring part provided outside the oxidation chamber via a monitoring window of the oxidation chamber while the oxidation process is interrupted; and 
 obtaining the oxidation rate based on a size of the current constricting part or the current injecting part that is monitored by the monitoring part. 
 
 
     
     
       2. The method as claimed in  claim 1 , further comprising:
 obtaining an amount of additional oxidation that is to be made based on the oxidation rate; and 
 additionally oxidizing the semiconductor layer by the amount of additional oxidation. 
 
     
     
       3. A method for producing a semiconductor element, comprising:
 placing within a water vapor atmosphere a semiconductor sample that includes a mesa having a semiconductor layer including Al and As; 
 forming a current constricting part and a current injecting part that is surrounded by the current constricting part in the semiconductor layer by oxidizing the semiconductor layer from a peripheral end of the semiconductor layer appearing at an outer peripheral side surface of the mesa towards an inner radial direction so as to leave a central portion of the semiconductor layer non-oxidized; 
 interrupting an oxidation process at least once during oxidation of the semiconductor layer; 
 monitoring an oxidation rate of the semiconductor layer while the oxidation process is interrupted; and 
 spraying or blasting an inert gas onto the semiconductor sample within the oxidation chamber while the oxidation process is interrupted, 
 wherein said monitoring includes:
 moving the semiconductor sample within an oxidation chamber to a position where the mesa is adjacent to a monitoring part provided outside the oxidation chamber via a monitoring window of the oxidation chamber while the oxidation process is interrupted; and 
 
 obtaining the oxidation rate based on a size of the current constricting part or the current injecting part that is monitored by the monitoring part. 
 
     
     
       4. The method as claimed in  claim 1 , further comprising:
 utilizing the semiconductor element to form a vertical-cavity surface-emitting laser (VCSEL). 
 
     
     
       5. A method for producing a semiconductor element, comprising:
 placing within a water vapor atmosphere a semiconductor sample that includes a mesa having a semiconductor layer including Al and As; 
 forming a current constricting part and a current injecting part that is surrounded by the current constricting part in the semiconductor layer by oxidizing the semiconductor layer from a peripheral end of the semiconductor layer appearing at an outer peripheral side surface of the mesa towards an inner radial direction so as to leave a central portion of the semiconductor layer non-oxidized; 
 interrupting an oxidation process at least once during oxidation of the semiconductor layer; 
 monitoring an oxidation rate of the semiconductor layer while the oxidation process is interrupted; and 
 supplying an inert gas at a low temperature onto the semiconductor sample while the semiconductor sample is within an oxidation chamber while the oxidation process is interrupted, to replace the water vapor atmosphere within the oxidation chamber with the inert gas and to cool the semiconductor sample. 
 
     
     
       6. The method as claimed in  claim 1 , wherein the oxidation process is interrupted at a predetermined timing prior to the oxidation reaching a predetermined final oxidized state. 
     
     
       7. The method as claimed in  claim 6 , further comprising:
 determining said predetermined timing by subtracting a predetermined amount from a total required oxidation time.